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Search Results: 1 - 10 of 314030 matches for " Li G "
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3D DOPs for Positioning Applications Using Range Measurements  [PDF]
Binghao Li, Andrew G. Dempster, Jian Wang
Wireless Sensor Network (WSN) , 2011, DOI: 10.4236/wsn.2011.310037
Abstract: For terrestrial positioning, some applications require three dimensional coordinates. The Dilution of precisions (DOPs) for position systems using range measurement are reviewed and the average values of DOPs for different deployments of base station geometries are examined. It is shown that to obtain the lowest DOPs, the base stations for different types of positioning systems need to be deployed differently. Changing the N-sided regular polygon to an (N - 1)-sided polygon with one base station in the centre of the polygon can decrease the value of DOP in general for a pseudorange time of arrival (TOA) system but not for an absolute range TOA system. The height of the base station in the centre can also change the DOP significantly. The finding can be used to optimize the deployment of the base stations for range measurement positioning systems.
Financing Innovative Medicines in Mainland China: The Role of Commercial Health Insurance  [PDF]
Hong Li, Gordon G. Liu, Christoph Glaetzer
Chinese Studies (ChnStd) , 2013, DOI: 10.4236/chnstd.2013.23020
Abstract: The National Reimbursement Drug List (NRDL) is a key component of the current government-led insurance policy to provide access to basic medicines in mainland China; yet NRDL coverage is limited due to public budgetary constraints and new, innovative medicines are often excluded. This paper explores the potential role of commercial health insurance as an optional approach to financing medicines excluded by the NRDL. The current status of commercial health insurance (CHI) in Mainland China is reviewed and we discuss proposed changes that may be needed to develop an effective and sustainable commercial insurance program to provide the Chinese population with better access to innovative medicines not covered by NRDL.
Performance of Gas Turbine Film Cooling with Backward Injection  [PDF]
X. C. Li, G. Subbuswamy, J. Zhou
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.54B025
Abstract: Gas turbines have been widely used in power generation and aircraft propulsion. To improve the gas turbine performance, the turbine inlet temperature is usually elevated higher than the metal melting point. Therefore, cooling of gas turbines becomes very critical for engines’ safety and lifetime. One of the effective methods is film cooling, in which the coolant air from the discrete holes blankets the surface from the hot gas flow. The major issues related to film cooling are its poor coverage, aerodynamic loss, and increase of heat transfer coefficient due to strong flow mixing. To improve the cooling performance, this paper examined film cooling with backward injection. It is observed that film cooling with backward injection can produce much more uniform cooling coverage under different conditions, which include cases on flat surface with low or high pressure and temperature. The backward injection also performs better in the presence of blade curvature. The effect of other parameters on the film cooling is also reported. The numerical results are validated by simple experimental test in this study.
Vulnerability assessment of storm surges in the coastal area of Guangdong Province
K. Li,G. S. Li
Natural Hazards and Earth System Sciences (NHESS) & Discussions (NHESSD) , 2011,
Abstract: Being bordered by the South China Sea and with long coastline, the coastal zone of Guangdong Province is often under severe risk of storm surges, as one of a few regions in China which is seriously threatened by storm surges. This article systematically analyzes the vulnerability factors of storm surges in the coastal area of Guangdong (from Yangjing to Shanwei). Five vulnerability assessment indicators of hazard-bearing bodies are proposed, which are social economic index, land use index, eco-environmental index, coastal construction index, and disaster-bearing capability index. Then storm surge vulnerability assessment index system in the coastal area of Guangdong is established. Additionally, the international general mode about coastal vulnerability assessment is improved, and the vulnerability evolution model of storm surges in the coastal area of Guangdong is constructed. Using ArcGIS, the vulnerability zoning map of storm surges in the study region is drawn. Results show that there is the highest degree of storm surge vulnerability in Zhuhai, Panyu, and Taishan; second in Zhongshan, Dongguan, Huiyang, and Haifeng; third in Jiangmen, Shanwei, Yangjiang, and Yangdong; fourth in Baoan, Kaiping, and Enping; and lowest in Guangzhou, Shunde, Shenzhen, and Longgang. This study on the risk of storm surges in these coastal cities can guide the land use of coastal cities in the future, and provide scientific advice for the government to prevent and mitigate the storm surge disasters. It has important theoretical and practical significance.
Some properties of the functional equation (x)=f(x)+ ¢ 0 xg(x,y, (y))dy
Li. G. Chambers
International Journal of Mathematics and Mathematical Sciences , 1991, DOI: 10.1155/s0161171291000030
Abstract: A discussion is given of some of the properties of the functional Volterra Integral equation (x)=f(x)+ ¢ 0 xg(x,y, (y))dy. and of the corresponding multidimensional equation. Sufficient conditions are given for the uniqueness of the solution, and an iterational process is provided for the construction of the solution, together with error estimates. In addition bounds are provided on the solution. The results obtained are illustrated by means of the pantograph equation.
Visual Knowledge Recommendation Service Based on Intelligent Topic Map
G. Li,H. Lu
Information Technology Journal , 2010,
Abstract: Aiming to help users to effectively acquire and visualize target knowledge from massive, distributed and heterogeneous information sources, we designed a visual knowledge recommendation service system based on intelligent topic map. It includes knowledge organization, knowledge recommendation and visualization display. Knowledge logical organization model based on intelligent topic map extends the conventional topic map in structure and enhances its reasoning functions. Hot resources mining distinguish the different importance degree of knowledge nodes (topics or knowledge elements), interest trends predict the interested knowledge of users in the future and knowledge navigations provide a personalized navigation path for users. Moreover, recommendation results visualization based on intelligent Topic Map provides users with an intuitive, graphic and pellucid visual interface. Finally, a demonstration is given to elaborate the knowledge recommendation providing process.
Cdc13 at a crossroads of telomerase action
Vincent Géli
Frontiers in Oncology , 2013, DOI: 10.3389/fonc.2013.00039
Abstract: Telomere elongation by telomerase involves sequential steps that must be highly coordinated to ensure the maintenance of telomeres at a proper length. Telomerase is delivered to telomere ends, where it engages single-strand DNA end as a primer, elongates it, and dissociates from the telomeres via mechanism that is likely coupled to the synthesis of the complementary C-strand. In Saccharomyces cerevisiae, the telomeric G-overhang bound Cdc13 acts as a platform for the recruitment of several factors that orchestrate timely transitions between these steps. In this review, we focus on some unresolved aspects of telomerase recruitment and on the mechanisms that regulate telomere elongation by telomerase after its recruitment to chromosome ends. We also highlight the key regulatory modifications of Cdc13 that promote transitions between the steps of telomere elongation.
Simultaneous readout of two charge qubits
J. Li,G. Johansson
Physics , 2006, DOI: 10.1103/PhysRevB.75.085312
Abstract: We consider a system of two solid state charge qubits, coupled to a single read-out device, consisting of a single-electron transistor (SET). The conductance of each tunnel junction is influenced by its neighboring qubit, and thus the current through the transistor is determined by the qubits' state. The full counting statistics of the electrons passing the transistor is calculated, and we discuss qubit dephasing, as well as the quantum efficiency of the readout. The current measurement is then compared to readout using real-time detection of the SET island's charge state. For the latter method we show that the quantum efficiency is always unity. Comparing the two methods a simple geometrical interpretation of the quantum efficiency of the current measurement appears. Finally, we note that full quantum efficiency in some cases can be achieved measuring the average charge of the SET island, in addition to the average current.
Hadrons in Dense Matter and Medium Effects in Relativistic Heavy-Ion Collisions
G. Q. Li
Physics , 1997,
Abstract: Theoretical and experimental studies of hot and/or dense matter, such as is created in high-energy heavy-ion collisions, and encountered in compact objects in astrophysics, constitute one of the most active frontiers in nuclear physics. In these Lectures, we discuss various approaches to the description of hot and/or dense matter, including the simple Skyrme-type parameterization and relativistic Walecka-type models, as well as microscopic Dirac-Brueckner and QCD sum rule approaches. As density and/or temperature of the hadronic system increases, chiral symmetry is gradually restored, as indicated by the decrease of quark condensate. This has profound effects on the properties of hadrons, especially their masses. We review various theoretical predictions for hadron properties in dense matter. Experimentally, possible medium modifications of hadron properties can be studied through the measurements of particle spectra, flow, and particularly, electromagnetic observables. Particle production, especially the production of rare particles such as kaons, vector mesons, and antiparticles, provides useful insight into heavy-ion collision dynamics, and hadron properties in dense matter. Collective flows of various kinds are important observables in heavy-ion collisions. They probe essentially the entire reaction process, and thus are very useful for the determination of the reaction dynamics. They also reflect the properties of hadrons in dense matter. Electromagnetic signals are considered penetrating probes that may carry undistorted information about the early stage of high-energy heavy-ion collisions. We discuss various theoretical calculations of dilepton and photon production in heavy-ion collisions at SPS energies and various medium effects that have been proposed to explain the observed low-mass dilepton enhancement.
Trust--Region Problems with Linear Inequality Constraints: Exact SDP Relaxation, Global Optimality and Robust Optimization
V. Jeyakumar,G. Li
Mathematics , 2013,
Abstract: The trust-region problem, which minimizes a nonconvex quadratic function over a ball, is a key subproblem in trust-region methods for solving nonlinear optimization problems. It enjoys many attractive properties such as an exact semi-definite linear programming relaxation (SDP relaxation) and strong duality. Unfortunately, such properties do not, in general, hold for an extended trust-region problem having extra linear constraints. This paper shows that two useful and powerful features of the classical trust-region problem continue to hold for an extended trust-region problem with linear inequality constraints under a new dimension condition. First, we establish that the class of extended trust-region problems has an exact SDP-relaxation, which holds without the Slater constraint qualification. This is achieved by proving that a system of quadratic and affine functions involved in the model satisfies a range-convexity whenever the dimension condition is fulfilled. Second, we show that the dimension condition together with the Slater condition ensures that a set of combined first and second-order Lagrange multiplier conditions is necessary and sufficient for global optimality of the extended trust-region problem and consequently for strong duality. Finally, we show that the dimension condition is easily satisfied for the extended trust-region model that arises from the reformulation of a robust least squares problem (LSP) as well as a robust second order cone programming model problem (SOCP) as an equivalent semi-definite linear programming problem. This leads us to conclude that, under mild assumptions, solving a robust (LSP) or (SOCP) under matrix-norm uncertainty or polyhedral uncertainty is equivalent to solving a SDP and so, their solutions can be validated in polynomial time.
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